reddawg

Could someone please tell me what the reason for relocating the lift pump ,and where to move it to and do i need (or do they make)some kind of kit

Beast2B

the main reason for moving the lift pump is that an electric fuel pump is better at pushing fuel from the tank to the injection pump than it is at pulling the fuel from the tank to the injection pump. there a SO MANY options that a search on lift pump, FASS, Airdog, pusher pump, RASP will get you weeks worth of reading! are you trying to do it inexpensive? most vendors offer a pusher pump kit with an additional lift pump that mounts back near the fuel tank and assists the stock lift pump. do you want extra filtering? FASS and Airdog are excellent (pricey at $600+). do you want a mechanical replacement that keeps a constant pressure at all rpm? check out the RASP system.
sorry this is so long, but it's just practice for what's ahead in reading about lift pumps! BTW, i added a Diesel Dynamics pusher pump kit to mine.

reddawg

thanks for the reply. i wanted to try to go inexpensive. is there a web site for diesel dynamics. and also do you know if i can just relocate stock pump.thank you for any info

Clunk

I have a Carter 4601hp(thanks BIGHEAD) pump installed in front of my fuel tank and mounted on the frame rail. This is how I installed it.
I let the fuel level get down to 1/4 tank, disconnected the battery cables, set the parking brake...you know the drill..drained the fuel filter by opening the water in fuel valve & let it pour into a drain pan then closed the valve.
I removed the old lift pump, removed the fuel line but left the fitting on my filter, then raised the front of the truck and supported it with jack stands high enough so I could work and kinda judged it to be high enough to keep fuel from pouring out of the fuel tank onto me when I cut the fuel supply line.
I lowered the fuel tank to lift pump supply line so fuel could pour into the drain pan and determined the front of the truck was higher than the fuel level in the fuel tank so I could proceed with the job.
After determining a clear place for the new pump and cutting the fuel supply line, I disconnected the front driveshaft at the front differential and tied it up out of the way so I could get a drill in there.
Using the supplied mounting bracket, I located where to drill the holes into the frame rail and drilled them. Because the frame rail is boxed, I used the drill size recommended on the fine thread 5/16 tap (I forget what size), drilled & tapped the holes and installed the bracket. I put some red Loctite on the bolts and just pulled them snug because of the the frame is kinda thin and let the red Loctite take a set and hold the bolt's in place. Following the instructions, I installed the lift pump with fittings on to the bracket, put a short 3/8 fuel hose on the cut fuel supply line to the fitting on the inlet side of the fuel pump. I installed a 3ft. piece of 3/8 fuel hose from the fitting on the outlet side of the pump and connected the other end to the fuel filter fitting.
The original lift pump had a 2 wire plug in electrical connector and the Carter I bought doesn't so I cut the connector off, butt spliced, soldered and double heat shrink (shrunk,shrank?) insulated 2-3ft. pieces of same guage wire. I had to pull the original wires down between the starter and the engine block to have room to work...kinda close around the motor mounts.
After soldering 2 heavy ring connectors (not the 2 little ones supplied with the kit) on the new wrapped and trimmed to fit electrical wires, I connected one to each electrical post on the pump.
After rechecking all the hoses, clamps and wiring and the proximity of same to heat or moving parts and finding everything safe, I reconnected the front driveshaft and let the truck off the jackstands. After checking for leaks and finding none, I disconnected the fuel pressure guage line at one joint and put on an extension hose so I could bleed air & foam off the system into the drain pan before trying to start the engine.
I reconnected the battery cables.
After bumping the starter with the keyswitch, the new lift pump started and ran for around 20 seconds. No fuel came out and the end of the fuel line had a slight vacuum when I put my finger over it so I swapped the electrical connectors on the fuel pump and tried again. This time when I bumped the starter, fuel & air flowed out the line with good pressure. I bumped the starter 3 more 20 second cycles until the fuel coming out had no air showing then reconnected the fuel pressure guage line back to normal. Upon bumping the starter yet again and finding the fuel pressure at 15 psi, I started the motor. After starting, it chuckled a coupla times then idled smooth.
It has worked great since September.

Concerning the stock pump wires and where I have them on my Carter 6401hp,
the black wire with the white stripe is spliced to the wire going to the pump electric post nearest the inlet port.
The yellow wire with the black stripe is spliced to the wire going to the pump electric post nearest the outlet port......edited 4/29/05

Because my old lift pump still showed 7 psi pressure going down the road, I altered the wiring and fittings so I could install it as a spare in the event of the new Carter failing.
After connecting the inj. pump wire to my BD Comp, I've drilled the banjos & fittings but that's another story.

Beast2B

i see the pressure is 9psi WOT now, what was it before? ...and if you're moving it anyway, why not put it as close to the tank as possible (less pull, more push)?

reddawg

thanks to all that replyed i think i am going to order the diesel dynamics pump

Clunk

It's on the frame rail about a foot in front and the same level as the fuel tank.
Prior to the relocate, I had about 6-7psi WOT with the Comp on but inj. pump wire not yet connected.
After the relocate, I had 10 psi WOT and the inj. pump wire still not connected.
The pressure dropped to 7psi on 5X5 WOT with the inj. pump wire connected, that's why I fixed the banjo bolts and fittings to get it to 9psi....I guess I need to take some pics.

latitud_rt

Hey Clunk - great info.
You mentioned switching the wires at the pump to get it to flow correctly. Which wire (+) hooked up to which wire (color) at the factory harness?
I am going to add the Carter as a pusher. I just picked up a new factory lift pump yesterday because my current pump was 4-4.5 at WOT. I took it to the dealer and of course they said it was ok. I asked if they performed the flow test and they said they didn't need to as there were no problems with the pressures being seen. Anyway, I didn't want to take any chances so I bought a replacement pump from a local Cummins dealer for $175.

Beast2B

clunk, thanks for the info. so you moved yours to the same location the pusher pumps go. makes more sense now. personally, i just liked the fact that if either pump gets weak, the second pump will assist until you change the bad one. downside i've read is if one fails, you can't push/pull through a dead pump. hopefully i'l get some advanced notice of impending doom! although i guess if you only have one pump, and it fails, you're up the creek, too...

Clunk

Latitude_rt,
I'll look as soon as the rain quits here.

Beast2B,
You know like I do, most of these don't just quit. My last one just started losing a little pressure and since it wasn't enough pressure to provide enough fuel for what I wanted to add, I made the change. The old pump is now my spare.
I'm likely going to get some more fuel fittings to try to get a coupla more lbs of fuel pressure for the next trick.

Clunk

Latitude_RT,
Concerning the stock pump wires and where I have them on my Carter 4601hp(thanks BIGHEAD),
the black wire with the white stripe is spliced to the wire going to the pump electric post nearest the inlet port.
The yellow wire with the black stripe is spliced to the wire going to the pump electric post nearest the outlet port.
Do you intend to connect your pusher pump to the present pump and wires...I don't know that the circuit can handle 2 pumps at once.

BIGHEAD

Clunk do you mean a 4601HP carter. That is what I converted to. Is there a 6401 or did you get the numbers backwards. I have installed a 4601HP in the stock location & it has worked flawlessly. I just don't see that relocating is worth all the effort. I mean the pump is still only going to pull & push the amounbt of fuel it is designed to do. I did convert to a 3/8th line to the lift pump & 1/2 to the filter & from the filter to the VP44.

Clunk

Hey thanks BIGHEAD! I lose my way every now and then and need to be guided back in the row.
Yes , it's the 4601HP...hadta go to the Summit site to know for sure.
I work around some pretty big pumps and they work better when there's positive suction head going to them. It'll be real easy to change now after this one lets go too.
I'm going to edit the pump numbers in the previous posts now, again thanks.

latitud_rt

Thanks again Clunk.
I am going tho use the factory circuit to trigger a relay for the additional pusher. I just needed to know which wire to pull the signal from as I assumed one of them was ground. I am ordering the pump next week. At the same time, I will be getting the fittings and hose to switch to a larger flow fuel lines. I already have larger banjo's, but I need more.

dan239

Clunk

What fitting did you use at the filter housing to connect the 3/8" hose?

Also what is the stock hose size from the tank? What size connector did you use to connect the 3/8" hose to it?

I am considering doing the same thing to my truck. Did you make any mistakes that I should avoid or anything that you would do different next time?

Thanks
Daniel